Concrete slab forming machine



Aug. 11, 1964 Filed. Nov. 1, 1962 I I I l I I I I I I l I I I l I l I I I I I I I l A. KALNS CONCRETE SLAB FORMING MACHINE 5 Sheets-Sheet 1 INVENTOR.

ARVIDS KALNS.

HIS ATTORNEY.

8" 1, 1964 A. KALNS 3,143,782

CONCRETE SLAB FORMING MACHINE Filed Nov. 1, 1962 5 Sheets-Sheet 2 1 1 E I? t i a w n Q m Q w I E Q I 31 N I 2 l w E LL 8 3 Lt F 3 7 INVENTOR. ARVIDS KALNS. er oOMfAM HIS ATTORNEY.

Aug. 11, 1964 A. KALNS CONCRETE SLAB FORMING MACHINE 5 Sheets-Sheet 3 Filed Nov. 1, 1962 INVENTOR.

KALNS HIS ATTORNEY.

Aug. 11, 1964 KALNs 3,143,782

CONCRETE SLAB FORMING MACHINE Filed Nov. 1, 1962 5 Sheets-Sheet 4 2|2 2|0 g 0 FIG? 214 1 266 2|2 I 264 i i INVENTOR.

ARVIDS mums. 8) AM 21M HIS ATTORNEY.

Aug. 11, 1964 A. KALNS CONCRETE SLAB FORMING MACHINE 5 Sheets-Sheet 5 Filed Nov. 1, 1962 FIG. 9

INVENTOR.

KALNS.

HIS ATTORNEY.

United States Patent 3,143,782 CUNCRETE SLAB FORMING MAQHINE Arvid Kalns, 1319 Court St, Syracuse, NSY. Filed Nov. 1, 1962, Ser. No. 234,712 Claims. (Cl. -41) This invention relates to and has as a general object a new and improved concrete slab forming machine. The machine comprising the preferred embodiment of this invention constitutes an improvement over the invention disclosed and claimed in my copending application, Serial Number 88,885, filed Feb. 13, 1961.

It was found that in the machine comprising the embodiment of the invention disclosed in that application certain improvements were necessitated to properly form a concrete slab of uniform density. These improvements relate to the means for compacting the concrete around cores, or mandrels to form voids in the finished concrete slab.

Accordingly, it is a more specific object of this invention to provide a slab forming machine having new and improved means for compacting the concrete around the cores to form a slab having the uniform density.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

In the drawings FIGURE 1 is a fragmentary cross-sectional side elevational view of the forward portion of the machine embodying the invention.

FIGURE 2 is a cross sectional side elevational view of the rear portion of the machine shown in FIGURE 1.

FIGURE 3 is a cross-sectional view taken approximately on line 33 of FIGURE 1.

FIGURE 4 is a cross-sectional view taken looking in the direction of the arrows on line 44, FIGURE 1.

FIGURE 5 is a cross-sectional view taken looking in the direction of the arrows of line 5-5, FIGURE 1, and

FIGURE 6 is a cross-sectional view taken looking in the direction of the arrows of line 66, FIGURE 1.

FIGURE 7 is a circuit diagram, schematic in nature, of the control circuitry for the machine.

FIGURE 8 is a fragmentary cross-sectional elevational view of a portion of the machine.

FIGURE 9 is a view similar to FIGURE 8 with the parts shown in a ditferent position.

FIGURE 10 is a perspective view taken approximately on line 10-10 of FIGURE 8.

FIGURE 11 is a perspective view taken approximately on line 1111 of FIGURE 9.

The machine as seen in FIGURES 1 and 2 consists of a carriage having a pair of side members 10 and 12 of hollow box shape extending in parallel spaced relation and fixed in this relation by a plurality of cross members, the forwardmost of which is L-shaped in cross section and indicated by reference numeral 14, and a plurality of box-shaped cross members, one of which is shown in FIGURE 1, and is indicated by reference numeral 16. Carried between the side members 16 and 12 at the forward end thereof is a top plate member 18, which together with the side members 10 and 12, and the fiat supporting surface for the machine, such as a floor surface 22, comprises the slab mold, or forming cavity 24. Fixed to each of the side members 19 and 12 are a plurality of L-shaped plates 26, to the underside of which is fixed a U-shaped bracket 28. Journaled between the legs of the bracket 28 is a grooved wheel 30 mounted for movement on a track 32 carried by plate 34.

3,143,782 Patented Aug. 11, 1964 ice With this arrangement, the entire machine moves over the floor 22 along the rails 32. It will be noted that the side members It? and 12 terminate in close proximity to the floor 22 and are provided on their inner surfaces with plates 36 which serve to form the sides of the concrete slab with indentations complementary in outline to the plate 36, for interlocking the slabs when used in construction, as will be understood.

A plurality of core forming members or mandrels 38 are mounted in the formed cavity 24 in spaced parallel relationship and the cores 38 serve to form voids in the concrete slab to reduce the over-all weight thereof. The cores 38 are provided at their rearward ends with rearwardly extending support arms 40, which arms are fixedly connected to the box-shaped cross member 16 by means of a pair of depending arms 42 and 44 which are apertured at their lower ends to receive a bolt 46 which passes also through the arms 40, see FIGURE 3. While the arms 48 have been shown as solid in cross section, it will be understood that these arms may also be hollow box-shaped members, and this is a matter of choice.

Referring now to FIGURE 2, it will be seen that the arms 48 extend rearwardly of the side plates 10 and 12 which are also braced apart at their rearward ends by means of the box-shaped cross members 48, 50 and 52. Depending from the members 50 and 52 which are fixed together are a pair of arms, only one of which, 54, is shown in FIGURE 2, and through the lower ends of which passes a bolt, or the like 56, this bolt also passing through the arm 40 to further support the arms 40, and in turn the cores 38 in the machine.

The bolts 46 and 56 are mounted in elongated apertures (not shown) formed in the arms 48 by means of yieldable bushings made of a flexible material, such as rubber or the like, whereby the arms, and in turn the cores 38, may be reciprocated linearly in small amounts by the mechanism to be next described.

The rearward terminus of the arms 40 are provided with clevis brackets 58 which are connected to a pin 60 carried by the plate 62. A plurality of these plates 62, which are reinforced with angle members 64 and 66, are fixedly connected as by welding to a cross shaft 68, the shaft 68 being mounted to span the side plates 10 and 12, and journalled at its opposite ends in bearings to permit I oscillation of the shaft 68. The plates 62 are connected to a channel shaped member 78 on which is mounted by means of bolts, or the like, 72, an electrical vibrator 74. By this arrangement, it will be understood that when the vibrator 74 is energized the plates 62 oscillate on the shaft 68 to reciprocate the arms 40, and in turn cores 38 in substantially an axial direction lengthwise of the concrete slab to be formed by the machine. This vibration of the cores serves to compact the concrete therearound, and to permit movement of the cores rearwardly with the entire machine on the rails 32.

Referring now to FIGURE 1, it will be seen that the top plate 18 is afiixed at its forward end to a tube 76 which is journalled on a shaft 78 extending between and atfixed to the side members 18 and 12. The rear edge of the plate 18 which terminates just above the rear face of the core 38 and is located beneath an angle shaped cross member 88, which is affixed by any suitable means, such as welding or the like, to the rear end of plate 18.

An L-shaped member having a horizontally extending leg 81 is atfixed at the lower end of its vertical leg to the cross member 80. Mounted by rubber bushings 82 in the leg 81 are one or more bolts 83, as by nuts or the like 84. The lower terminus of the bolts 83 are fixedly connected to the top of the side members 10 and 12, whereby the plate 18 may be adjusted by means of the bolts 83 and nuts 84. Plate 18 is also provided with an electrical vi brator 86 mounted thereon in any suitable manner, as by a channel member 85 having a plurality of legs 87 welded to plate 18 so that energization of the vibrator 86 will serve to linearly reciprocate, in limited amounts, the plate 18 to compact the concrete around the cores 38, and prevent adherence of the'plate 18 to the top of the concrete slab.

Located a spaced distance rearwardly of the rear end of plate 18 so as to form a discharge aperture 88 is an angle member 90. The member 90 is athxed between side members and 12, and between upstanding box frame members 92, the members 92 being four in number, and fixed at their lower ends to the side plates 10 and 12 by the bolted angle brackets 91 and 93. The upper ends. of the frame members 92 are fixed to channel shapedcross members 94 for a purpose to be hereinafter described.

, Fixedto the members 82 and 90 are the front and rear walls 96 and 98, respectively, of a discharge hopper 99 having side walls 100 and a scraper blade 102. Mounted between the side walls of the hopper is a cross shaft 104 extending through the exterior of the side wall 100 and connected to any suitable drive means so as, to effect rotation of the shaft 104. Aifixed to the shaft 104 are a plurality of truncated cones 106 braced together by plates 108 so as to form discharge cavities 110. These cavities are filled with the relatively dry concrete mix, and rotation of the shaft 104 serves to discharge the mix through the aperture 88 into the slab forming cavity 24,- at the rear of the cores 38. It will be appreciated that the shaft 104 and the members 106 form a paddle wheel type arrangement 107' for effecting the infeed of the concrete mix.

Fixedly mounted on the upper surfaces of the cross arms 94 are a pair of channel members 114 and 116. lournaled in end slots formed in channel members 114 and.116, and connected to any suitable drive means are the trunnions 120 and 122 of rollers 124 and 126 located between the side plates 114 and 116. Entrained over the rollers 124 and 126 is an endless conveyor belt 128 having. an upper run 130 which passes over a channel shaped cross member 132, welded between the members 114,

which serves to support the underside of the upper run 130 of the conveyor belt 128. Upper flange of the channel shaped member 114 has the flange 134 of an L-shaped member 136 afiixed thereto as by means of bolt 138. The top of flange 136 has the side walls 140 and 142 of a feed hopper 143. aflixed therethrough by any suitable means such as welding, and the rear wall 144 is aflixed to an angle shaped cross member 146 carried between the side members 136 and 137. The front wall 148 of the feed hopper is affixed at its lower end to an angle shaped cross member 150 afiixed at its ends to the members 136 and 137.;

By this arrangement, it will be seen that the concrete mix dumped into the feed hopper 143 passed therethrough on to the top run 130 of the conveyor belt, which, when rotated in a counterclockwise direction, will serve to feed the mix out of the feed hopper 143 and into the discharge hopper 99. The amount of concrete fed into the hopper 99 may be regulated by means of an adjustable-gate 152 carried between side members 13 6 and 137 by means of a pair of shafts 154 and 156 to which the gate 152 issuitably fixed, the shafts 154 and 156 being journaled in bushings 157 mounted on the side members 136 andp137. The feed drive means (not shown) for conveyor 128 and paddle wheel 107 is arranged to rotate the paddle wheel at approximately four times the speed of conveyor 128. 7

Referring nowto FIGURES 1, 5, and 6, the means for feeding or extruding the concrete dumped into the rear of the cavity 24 adjacent the feed aperture 88 will be described. Mounted between the side plates 10 and 12 is a ram plate 160 extending across the entire span between the sides10 and 12. The ram plate 160 is formed with :1 depending leg 162 and a rearwardly extending leg 164.

The depending leg 162 is received between side members 10 and 12 and is formed with a plurality of apertures equal in number to the number of cores 38. These apertures, indicated by the reference numeral 166 in FIG- URE 6, are of a form complemental to the cross sectional form of the core 38 and are over-size so as to permit the apertures to pass over the end of the core 33. The ram plate is also formed with a plurality of slots 168 positioned in the vertical portion 162 between the apertures 166. Reinforcing wire, or the like, such as strands of pre-stressed steel cable may be positioned on the floor surface 22 so as to be located in these apertures.

Aflixed to the rearward end of the leg 164 of ram plate 160 are a plurality of rearwardly extending arms 170, the outside two of which have a pair of rollers 172 aflixed thereto as by means of bolts 174, see FIGURE 3. The rollers 172 are received in a pair of channel shaped members 176 which are afiixed to the inner surfaces of the side members 10 and 12. Fixed to the rear of the arms is a Z-shaped cross. member 180 so as to interconnect the arms 170. The arm 180 is provided at its center with a clevis 182 which is apertured to receive a pin 184 to connect to the bracket 186 carried by the piston rod 188 of anextruding cylinder 190. The rear end of the cylinder 190 is connected by a bracket 192 and pin 194 to a clevis 196 aifixed to the center of the cross members 50 and 52. As will be obvious, this arrangement permits the movement of the ramplate 160 forwardly over the arms 40 toward the cores 38 when fluid is admitted under pressure to the rear of cylinder 190, and retraction of the ram plate 160 from the rear face of the cores 38 on the arms 40 when the fluid pressure is admitted to the forward end of the cylinder 190.

One of the novel portions of the preferred embodiment of the invention comprises a plurality of sleeves or troughs which are U-shaped in cross section, and are affixed to the rear face of the leg 102 of the ram plate 160, these troughs being identified by the reference numeral 200. During the forward feed of the ram plate 160, the excess of the concrete fed through the aperture 88 will be received and collected in thesleeves 200. This excess, or overfeed, will be discharged upon the rearward movement of the plate 160 by means of a stripping plate 202 affixed to the core arm 40' by means of an angle bracket 204 and bolts 206. The stripper plate 202 has an outline complemental to the cross-sectional outline of the interior surface of the sleeve 200, so as to discharge, all of the excess concrete in the sleeve 200 into the form cavity 24 beneath the feed aperture 88. This arrangement and construction is best seen in FIGURE 6.

Also, any concrete adhering to the arm 40 and compacted thereon during the forward feed of the ram 160 will be removed on rearward movement of the ram 160 by virtue of a pair of scraper knives 208 and 210, which are positioned on the rear face or" the depending leg 162 of the ram plate 160 at the forward end of the sleeve trough 200, and in spaced relation on each side of the arm 40. As will be understood, the scraper knives 208 and 210 will serve to scrape the concrete off the arms.

40 and to discharge it into the bottom of the trough 200 upon rearward movement of the plate 160, and the scraper plate 202 will discharge thisconcrete by virtue of the action previously described. The combination of the scraper plate and scraper knives serves to prevent jamming, or fouling of the ram plate mechanism, and to properly compact and feed the concrete around the bottom of cores 38 to form the slab of uniform density, and this construction forms the novel portion of this invention.

It will be seen in FIGURES 1 and 4 that the cores 38 are formed with long tapering surfaces 320. These tapers on the rear ends of the cores 38 aid in the compaction of the cementitious material during the intermittent movement of the cores 38 rearwardly with the machine during each feeding and extruding cycle to form the concrete slab.

The control circuit for the machine is shown in FIG- URE 7 and comprises a 440 volt power supply comprising a hot line 210 and a common line 212, which is provided with a double pole single throw switch 214.

The control circuit as shown is largely schematic and includes an impulse counter indicated by the box 218, a feeder motor solenoid operated hydraulic valve 220 having a solenoid 221, a hydraulic valve 222 for operating extruding cylinder 199, having a forward feed solenoid 224, and a reverse feed solenoid 226, a limit switch 228 so arranged as to be moved into engagement with either of the contacts 230 or 232 upon completion of the forward and reverse feed cylinder 222. The control system further includes a pair of core vibrators 74 and a pair of top plate vibrators 35. The power supply lines 219 and 212 are connected to the primary of a step-down transformer 234 having a secondary winding 236 to give a 220 volt power supply for the timer 218, valve 221) and solenoids 224 and 226. Further, the control circuit includes a pair of solenoid operated relays, one for the vibrators 74 indicated by reference numeral 238, and one for the vibrators 86 indicated by the reference numeral 240. The vibrators 74 and 86 are connected to the voltage lines 218 and 212 by a parallel circuit comprising lines 242 and 244, lines 246 and 248 having a double pole single throw switch 250, and lines 252 and 254 having a similar switch 256.

Briefly described, the cycle of operations is as follows: The feeder motor (not shown) for the conveyor 128 and paddle wheel 167 is actuated by means of the valve 220. After a predetermined amount of time has elapsed, and the discharge hopper paddle wheel has fed a quantity of cementitious material through the discharge aperture 88 into the mold cavity 24, the counter 21S serves to stop the feed motor and to energize the forward feed solenoid 224 to start the extrusion stroke of cylinder 190, which is the forward feed of the ram plate 169. When the plate 169 reaches its forwardmost point of travel, the limit switch 228 is contacted to energize the reverse feed solenoid 226 to return the ram plate 160 to its rearwardrnost position during which the stripper plate 202 and scraper blades 208 and 210 function to discharge the overfeed, or excess of the cementitious material out of the sleeves 2%. When the return feed of the ram plate 160 is completed, the limit switch 228 is again engaged to energize the counter and commence the feeding cycle for the feed conveyor 128 and paddle wheel 107 to repeat the cycle.

The operation of the control circuit is as follows: The hot line 260 is connected by the arm of limit switch 228, which is in the dash line position, in engagement with contact 228 during the feed cycle of the machine to line 262, which is connected to counter 218 and to the return side 264 of the transformer 234 by line 266 to energize the counter 218. Impulse counter 218 is of any suitable commercially available type and serves when energized to connect the hot feed on line 262 by line 268 through the solenoid 221 of the feed valve 220 to the common side 264 of the circuit by line 270 thereby energizing the solenoid 221. The energization of the solenoid 221 serves to actuate the valve 220 so as to energize the drive motor for conveyor 128 and paddle wheel 107 to feed the cementitious material through aperture 88 and into the form cavity 24 in the rear of cores 38. After a predetermined amount of material has been fed into the cavity 24, which is controlled by the number of impulses received by counter 218, at least one impulse being received for each revolution of wheel 107, the circuit to the solenoid 221 is broken in the counter 218 to deenergize the solenoid 221 and return the valve 220 to its closed position to halt the operation of the feed motor and stop any further infeed of the cementitious material.

At the same time, the hot feed on line 262 is now con nected by counter 218 to line 272 and through the forward solenoid 224 of valve 222 for the extrusion cylinder 1% to line 274, which is connected to the common line 264, thus energizing the solenoid 224 and actuating valve 222.

During the feed cycle, the hot line 210 is connected through closed switch 214 to line 242 and through the closed switches 250 and 256 to line 276 and 278, respectively. The lines 276 and 278 are connected through the normally closed contact and armature of relays 238 and 240, respectively, through variable resistors 280 and 282, respectively, to lines 284 and 286 and through branch circuit lines 288 and 2%, respectively, through each pair of vibrators 74 and 86, and through the closed switches 25% and 256 to line 244, which is connected to the common line 212. This circuit serves to energize the vibrators 74 and 86 at a low rate during the feed cycle of operation. Each of the lines 276 and 278 are connected by lines 292 and 294, respectively, through variable resistors 2% and 298, which are connected at their opposite sides by lines 284 and 286 through vibrators, as previous ly described. The resistors 296 and 228 are so adjusted as to give a high rate of vibration during the extrusion cycle of the machine, as will be hereinafter described. In addition, each of the lines 276 and 278 is provided with a rectifier 3% and 382, respectively, to rectify the voltage supplied to the vibrators, as will be understood.

Accordingly, when the hot feed is placed on the line 272 by counter 218, as previously described, the relays will be energized through lines 304 and 386, which are connected through the coils of relays 238 and 2411, respectively, to the common return line 264. The energization of the relays 238 and 240 will serve to break the low rate vibration circuit through the variable resistors 28% and 232 to cause the vibrators 74 and 86 to be vibrated at a high rate during the extrusion cycle. After the ram plate 168 has reached the forwardmost point of its travel, due to the energization of the forward feed solenoid 224, which serves to connect a source of fluid under pressure through the actuated valve 20 to the rear of the extrusion cyclinder 190, the limit switch 228 will be moved out of engagement with the contact 230 and into engagement with the contact 232. This will serve to break the circuit to the forward feed solenoid 224 and to complete a circuit from the hot line 260 through line 363 and reverse feed solenoid 225 to line 310, which is connected to the common return line 274, thus energizing reverse feed solenoid 226. The energization of solenoid 225 will actuate the valve 222 so as to disconnect the fluid pressure supply from the rear of cylinder 190 and to connect the fluid pressure supply to the forward end of the cylinder, thus causing the ram plate to be moved rearwardly. As above described, the vibrators 74 and 86, due to the de-energization of the solenoids 238 and 246 will be vibrated at a low rate during this return cycle. The solenoids 233 and 240 are de-enengized when the limit switch 228 is moved out of engagement with the contact 239, as will be understood. When the ram plate 160 reaches the rearwardmost point of its travel, the armature 228 is again moved into engagement with the contact 238 to again energize the counter 218 and to start another cycle. The fluid motor for operating the feed conveyor 128 and paddle wheel 107 has not been shown and may be of any conventional form, so geared and arranged as to rotate the paddle wheel at approximately four times the speed of the conveyor 128.

This arrangement, together with the overfeed troughs 200, stripper plates 282 and scraper knives 268 and 210 for each arm 40 of the cores 38 result in a machine which operates to form concrete slabs of uniform density having strengths in compression and tension which exceed minimum requirements.

The operation of the novel portion of the invention comprising the subject matter of this application is clearly 'shown in FIGURE 8.

, illustrated in FIGURES 8 to 11, inclusive. In FIGURE 8; the ram plate'160 has been shown in its forward feed position of the extruding cycle.

In this position, the cementitious material identified by the letter C is shown -packed around the core member 38, this packing and filling being effected by the ram plate 160. However, the excess, or 'overfeed 'of the cementitious material is also received in the collecting trough 200 during the forward titiousmaterial passing through these apertures and into i the sleeve 200.

FIGURE '9 illustrates the discharge of this excess, or overfeed of the cementitious material into the bottom of v the mold cavity 24. In that figure, the core 38 and arm 49, which are stationary are in the same position as Accordingly,'the ram plate 160 has returned to its initial position, during which return movement the stationary stripper or scraper plate 202 serves to force the cementitious material C out of the sleeve 200 and into the bottom of the cavity 24. In addition, the scraper knives, or blades 208 and 216 have scraped the arm 4-0 to clean away any cementitious material deposited on, or adhering to the arm 40. The extrusion cycle is again then repeated, during which time the scraper blades also scrape the arms 40, and consequently it will be understood that for each feed and return movement of the ram plate 160, the stripping and scraping action of the plate 2&2 andblades 2&3 and 219, respectively, willoccur during the return and forward movements of the ram 160.

FIGURES 10 and 11 are perspective views illustrating the arrangement shown in the positions of FIGURES 8 and 9, respectively. It will be noted that the core members 38, as shown in FIGURES 10 and 11, are hollow to reduce the over-all weight of these members, and are integrally formed with the arms 40. As will be understood, this showing is made for purposes of illustration only, and the core members and arms could be formed and connected in any suitable manner. Finally, the exteriorend portions of the cores 38 are formed with sloping surfaces, generally indicated by the reference numeral 320, these surfaces extending from a maximum width at the rearward ends of the cores, and tapering outwardly toward the centers of the cores. These sloping surfaces serve to aid in the compaction of the cementitious material when the cores are vibrated, and also serve to permit and facilitate withdrawal of the cores 38 from the slab as the complete machine moves rearwardly on the rails 32 during the slab forming process.

What I claim is:

1. A concrete slab forming machine comprising a carriage adapted for movement along a track over a flat surface, said carriage having a top plate spaced upwardly from said surface and a pair of side members, the lower edges of said side members terminating in close proximity to said surface, said top plate, side members and surface forming a mold cavity, a plurality of core members mounted in spaced parallel relation in said cavity, said core members extending lengthwise of said cavity and spaced from said surface, top plate and side members, and being carried by support arms extending rearwardly of said carriage, a hopper for cementitious material -mounted on said carriage, a discharge passage for discharging cementitious material between said side members and about the rear portions of said core members, a

ram plate located a spaced distance rearwardly of said core-members and normally positioned rearwardly of said discharge passage, said ram plate being formed with clearance apertures for said core'members, a collection sleeve carried on the rearward side of said plate around each of said apertures, power means for moving said ram plate toward said core members subsequent to the dis- Li charge of cementitious material through said discharge passage to compact said material about said cores, the overflow of said material being collected in said sleeves, each of said support arms having a stripper plate atlixed thereto of a shape complemental to said sleeves and located in said sleeves, said stripper plates stripping said excess cementitious material out .of said sleeves upon rearward movement of said ram plate, and power means for vibrating said top plate and cores, respectively.

2. A concrete slab forming machine comprising a carriage adapted for movement along a track over a fiat surface, said carriage having a top plate spaced upwardly from said surface and a pair of side members, the lower edges of said side members terminating in close proximity to said surface, said top plate, side members and surface forming a mold cavity, a plurality of core members mounted in spaced parallel relation in said cavity, said core members extending lengthwise of said cavity and spaced from said surface, top plate and side members, and being carried by support arms extending rearwardly of said carriage, a hopper for cementitious material mounted on said carriage, a discharge passage for discharging cementitious material between said side members and about the rear portions ofsaid core members, a ram plate located a spaced distance rearwardly of said core members and normally positioned rearwardly of said discharge passage, said ram plate being formed with clearance apertures for said core members, said clearance apertures having a shape complementary to the shape of said core members, the rearward side of said plate being provided with axially extending collection troughs about said apertures, a stripper plate having a shape complementary to said troughs fixedly mounted on each of said support arms and initially positioned adjacent the forward end of said troughs, said stripper plate discharging the overfeed of said cementitious material collected in said troughs during forward movement of said ram plate, scraping means carried on the rearward side of said ram plate intermediate said ram plate and said stripper plate for cleaning said support arms of said cementitious material upon reciprocation of said ram plate on said arms toward and away from said core members and power means for reciprocating said ram plate.

3. A slab forming machine mounted for movement along a fiat surface, said machine comprising a top plate spaced upwardly from said flat surface, a pair of spaced apart side plates depending toward and terminating in close proximity to said fiat surface and forming therewith and with said top plate and a slab forming cavity, a plurality of core members: mounted in spaced apart relation in said cavity, said core members being also spaced from said top plate, side plates and flat surface, said core members being carried by support arms extending rearwardly of said machine, ram means located a spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members and ram means, means for reciprocating said ram means along said arms toward said cores to feed said cementitious material around said cores in said cavity, said ram-means being provided with clearance apertures whereby excess cementitious material will pass through said apertures on the forward movement of said -ram means, and means located rearwardly of said ram means for returning said excess cementitious material into said cavity upon the return movement of said ram means.

4. A slab forming machine mounted for movement along aflat surface, said machine comprising a top plate -spaced upwardly from said flat surface, a pair of spaced snee /s2 said machine, ram means located a spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members and ram means, means for reciprocating said ram means along said arms toward said cores to feed said cementitious material around said cores in said cavity, whereby excess cementitious material will pass through said apertures on the forward movement of said ram means and means located rearwardly of said ram means for returning said excess cementitious material into said cavity upon the return movement of said ram means, means for vibrating said top plate and core members in a substantially axial direction to compact said cementitious material and prevent adherence of said material to said cores and top plate.

5. A slab forming machine mounted for movement along a flat surface, said machine comprising a top plate spaced upwardly from said flat surface, a pair of side plates depending toward and terminating in close proximity to said flat surface and forming therewith and with said top plate and a slab forming cavity, a plurality of spaced apart core members mounted in said cavity, said core members being also spaced from said top plate, side plates and fiat surface, said core members being carried by support arms extending rearwardly of said machine, ram means located in spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members and ram means, means for reciprocating said ram means along said arms toward said cores to feed said cementitious material around said cores in said cavity, said ram means being provided with clearance apertures whereby excess cementitious material will pass through said apertures on the forward movement of said ram means and overfeed means located rearwardly of said ram means for returning said excess cementitious material into said cavity upon the return movement of said ram means, means for vibrating said top plate and core members in a substantially axial direction to compact said cementitious material and prevent adherence of said material to said cores and top plate, said overfeed means including a collection sleeve having a cross-sectional outline substantially complemental to core apertures formed in said ram means.

6. A slab forming machine mounted for movement along a flat surface, said machine comprising a top plate spaced upwardly from said flat surface, a pair of side plates depending toward and terminating in close proximity to said flat surface and forming therewith and with said top plate a slab forming cavity, a plurality of core members mounted in spaced apart relation in said cavity, said core members being also spaced from said top plate, side plates and flat surface, said core members being carried by support arms extending rearwardly of said machine, ram means located a spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members and ram means, means for reciprocating said ram mean-s along said arms toward said cores to feed said cementitious material around said cores in said cavity, said ram means being provided with clearance apertures whereby excess cementitious material will pass through said apertures on the forward movement of said ram means and overfeed means located rearwardly of said ram means for returning said excess cementitious material into said cavity upon the return movement of said ram means, means for vibrating said top plate and core members in a substantially axial direction to compact said cementitious material and prevent adherence of said material to said cores and top plate, said overfeed means including a collection sleeve having a cross-sectional outline substantially complemental to core apertures formed in said ram means, and stripping means comprising a scraper plate afiixed to said arms and located in said sleeve, said stripping means serving to scrape said arms upon rearward movement of said ram means to discharge cementitious material collected in said sleeve during the forward feed of said ram means.

7. A slab forming machine mounted for movement along a fiat surface, said machine comprising a top plate spaced upwardly from said flat surface, a pair of side plates depending toward and terminating in close proximity to said flat surface and forming therewith and with said top plate a slab forming cavity, a plurality of spaced apart core members mounted in said cavity, said core members being also spaced from said top plate, side plates and flat surface, said core members being carried by support arms extending rearwardly of said machine, ram means located a spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members and ram means, means for reciprocating said ram means along said rams toward said cores to feed said cementitious material around said cores in said cavity, and overfeed means located rearwardly of said ram means for collecting and discharging excess cementitious material into said cavity upon the return movement of said ram means, means for vibrating said top plate and core members in a substantially axial direction to compact said cementitious material and prevent adherence of said material to said cores and top plate, said overfeed means including a collection sleeve having a cross-sectional outline substantially complemental to core apertures formed in said ram means, and stripping means including a scraper plate affixed to said arms and located in said sleeve, said stripping means serving to discharge upon rearward movement of said ram means, cementitious material collected in said sleeve during the forward feed of said ram means, said stripping means further including a pair of scraper blades carried by said collection sleeve and ram means, said blades located intermediate the ram means and said scraper plate and being positioned to scrape said support arms free of said cementitious material during reciprocation of said ram means.

8. A slab forming machine mounted for movement alOng a fiat surface, said machine comprising a top plate spaced upwardly from said flat surface, a pair of spaced apart side plates depending toward and terminating in close proximity to said fiat surface and forming therewith and with said top plate a slab forming cavity, a plurality of spaced apart core members mounted in spaced apart relation in said cavity, said core members being also spaced from said top plate, side plates and flat surface, said core members being carried by support arms extending rearwardly of said machine, ram means located a spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members and ram means, means for reciprocating said ram means along said arms toward said cores to feed said cementitious material around said cores in said cavity, said ram means being provided with clearance apertures whereby excess cementitious material will pass through said apertures on the forward movement of said ram means and means located rearwardly of said ram means for returning said excess cementitious material into said cavity upon the return movement of said ram means, said core members being formed with a tapered surface extending from substantially the middle portion thereof and tapering toward the axis of said core members at one end thereof.

9. A slab forming machine mounted for movement along a flat surface, said machine comprising a top plate spaced upwardly from said flat surface, a pair of spaced apart side plates depending toward and terminating in close proximity to said fiat surface and forming therewith and with said top plate and a slab forming cavity, a plurality of core members mounted in spaced apart relation in said cavity, said core members being also spaced from said top plate, side plates and flat surface, said core members being carried by support arms extending rearwardly of said machine, ram means located a spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members and ram means, means for reciprocating said ram means along said arms toward said cores to feed said cementitious material around said cores in said cavity, ram means being provided with clearance apertures whereby excess cementitious material will pass through said apertures on the forward movement of said ram means and means located rearwardly of said ram means for returning said excess cementitious material into said cavity upon the return movement of said ram means, power means for vibrating said top plate and said core members, control means for controlling the vibration of said top plate and core members to cause vibration thereof at a relatively high rate during said forward movement of said ram means, and at a relatively low rate during the rearward movement of the ram means and during the time when the cementitious material is discharged into said cavity.

10. A slab forming machine mounted for movement along a flat surface, said machine comprising a top plate spaced upwardly from said flat surface, a pair of spaced apart side plates depending toward and terminating in close proximity to said flat surface and forming therewith and withsaid top plate a slab forming cavity, a plurality .of spaced apart core members mounted in said cavity,

said core members being also spaced apart from said top plate, side plates and fiat surface, said core members being carried by support arms extending rearwardly of said machine, ram means located a spaced distance rearwardly of said core members, means for discharging cementitious material into said cavity intermediate said core members i2 and ram means, means for reciprocating said ram means along said arms toward said ccresto feed said cementitious material around said cores in said cavity, said ram means being provided with clearance apertures whereby excess cemen-titious material will pass through said apertures on the forward movement of said ram means and means located rearwardly of said ram means for returning said excess cementitious material into said cavity upon the return movement of said ram means, means for vibrating said top plate and core members in a substantially axial direction to compact said cementitious material and prevent adherence of said material to said cores and top plate, control means for said means for vibrating said top plate and core members, said control means being operable to vibrate said top plate and core members at a relatively high rate as said cementitious material is fed forwardly by said ram means and at a relatively low rate as said ram means is returned to its initial position, and

during the discharge of the cementitious material into said cavity.

References Cited in. the tile of this patent UNITED STATES PATENTS 272,410 Campbell Feb. 20, 1883 2,938,255 Oakden May 31, 1960 2,948,942 Gordon Aug. 16, 1960 FOREIGN PATENTS 52,735 Austria Mar. 26, 1912 OTHER REFERENCES Roth, German application 1,118,684, printed Nov. 30, 1961.

UNITED STATES PATENT ()FFICE CERTIFICATE OF vCORRECTION Patent No 3,143,782 August 11, 1964 Arvid Kalns It is hereby certified that error appears in the above-numbered pat- ,ent requiring correction and that the said Letters Patentshould read as corrected below.

Column 4, line 7, for "core 331" read core 38, column 6, line 41, for "20" read 220 column 9, line 6, after "cavity," insert said ram means being provided with clearance apertures column 10, line 18, for "rams" read arms Signed and sealed this 8th day of December 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER A ttcsting Officer Commissioner of Patents 

1. A CONCRETE SLAB FORMING MACHINE COMPRISING A CARRIAGE ADAPTED FOR MOVEMENT ALONG A TRACK OVER A FLAT SURFACE, SAID CARRIAGE HAVING A TOP PLATE SPACED UPWARDLY FROM SAID SURFACE AND A PAIR OF SIDE MEMBERS, THE LOWER EDGES OF SAID SIDE MEMBERS TERMINATING IN CLOSE PROXIMITY TO SAID SURFACE, SAID TOP PLATE, SIDE MEMBERS AND SURFACE FORMING A MOLD CAVITY, A PLURALITY OF CORE MEMBERS MOUNTED IN SPACED PARALLEL RELATION IN SAID CAVITY, SAID CORE MEMBERS EXTENDING LENGTHWISE OF SAID CAVITY AND SPACED FROM SAID SURFACE, TOP PLATE AND SIDE MEMBERS, AND BEING CARRIED BY SUPPORT ARMS EXTENDING REARWARDLY OF SAID CARRIAGE, A HOPPER FOR CEMENTITIOUS MATERIAL MOUNTED ON SAID CARRIAGE, A DISCHARGE PASSAGE FOR DISCHARGING CEMENTITIOUS MATERIAL BETWEEN SAID SIDE MEMBERS AND ABOUT THE REAR PORTIONS OF SAID CORE MEMBERS, A RAM PLATE LOCATED A SPACED DISTANCE REARWARDLY OF SAID CORE MEMBERS AND NORMALLY POSITIONED REARWARDLY OF SAID DISCHARGE PASSAGE, SAID RAM PLATE BEING FORMED WITH CLEARANCE APERTURES FOR SAID CORE MEMBERS, A COLLECTION SLEEVE CARRIED ON THE REARWARD SIDE OF SAID PLATE AROUND EACH OF SAID APERTURES, POWER MEANS FOR MOVING SAID RAM PLATE TOWARD SAID CORE MEMBERS SUBSEQUENT TO THE DISCHARGE OF CEMENTITIOUS MATERIAL THROUGH SAID DISCHARGE PASSAGE TO COMPACT SAID MATERIAL ABOUT SAID CORES, THE OVERFLOW OF SAID MATERIAL BEING COLLECTED IN SAID SLEEVES, EACH OF SAID SUPPORT ARMS HAVING A STRIPPER PLATE AFFIXED THERETO OF A SHAPE COMPLEMENTAL TO SAID SLEEVE AND LOCATED IN SAID SLEEVES, SAID STRIPPER PLATES STRIPPING SAID EXCESS CEMENTITIOUS MATERIAL OUT OF SAID SLEEVES UPON REARWARD MOVEMENT OF SAID RAM PLATE, AND POWER MEANS FOR VIBRATING SAID TOP PLATE AND CORES, RESPECTIVELY. 